As of recent years, shifting diet trends in American society have added more and more meat to the plate than ever before. In 2018, for example, a record meat consumption per capita was reached at approximately 222.2 pounds of red meat and poultry per American per year. Due to the cost of meat production, this statistic becomes rather worrisome given some of the prior posted concerns over land usage and water consumption. In the case of cattle, for example, nutrients are converted into beef at a rate of 54:1, resulting in an incredibly high loss in nutrients compared to a strictly plant-based diet. However, this statement is not as to say that veganism is the solution; in fact, other sources of protein are just about as efficient as grain production itself. To begin addressing the issue of higher meat consumption per capita, one must assess the alternative protein sources that can be focused on as a society to supplement the particularly costly red meats of pork and beef.
The Land-less Farm
Fig. 1 Jillian P. Fry. Feed Conversion Ratio
Among the most promising future farms to help produce food for a growing population without increasing problems with excess land usage is the idea of offshore fish farming. Rather than establishing themselves on land like traditional shore-based fish farms or inland like beef, pork, and poultry farms, offshore fish farms create an environment on a tethered base in the ocean, reducing unnecessary land usage while tapping into a more sustainable resource for food production. Compared to many other forms of meat production as shown in Figure 1, fish production, across the spectrum, largely outperforms beef and pork production by a significant margin while performing marginally better than poultry. As a diversified food source, the numerous different types of fish aquaculture is likely to help transition society to use less beef and pork in favor of more sustainable sources that only use as much as two pounds of feed per pound of fish on average. According to the study that derived the information for Figure 1, the Atlantic salmon begins to shine above all of the other fish, retaining over 25% of protein and calories from its feed, a statistic that is just slightly under that of the chicken.
Since, as mentioned earlier, much aquaculture is done near or on land, the water often becomes rather stagnant without proper filtration systems in place. Offshore fish farming, especially in deeper waters, severely mitigates this problem by allowing ocean currents to passively refresh water within the habitat, leading to healthier fish in the end. Additionally, the waste products from fish excrement in shore-based systems create a concentrated deposit on the ocean floor, significantly impacting the surrounding ecosystem. However, offshore aquaculture systems such as “Deep Sea Geodesic Dome Farms” tend to spread this waste out over a larger area of the ocean, providing nutrients in comfortable doses for the ocean to absorb. Additionally, more open environments reduce the prevalence of disease in fish, increasing the final quality and health of the food produced. Aside from fish aquaculture exclusively, a new form of aquaculture is rapidly emerging in recent years that seeks to surpass that of the chicken in nearly all aspects of efficiency: unfed aquaculture.
Unfed Aquaculture?
Fig. 2 ARC Marine. Mussel Farm
To begin, one must understand what exactly is unfed aquaculture? Unfed aquaculture is considered to be any form of aquaculture that can be raised without needing to supply external food outside of that produced in its ecosystem naturally. Examples of this type of aquaculture include organisms such as clams, muscles, and oysters which all filter feed from the surrounding water which carries nutrients from other sources in the ocean. When grown in offshore farms, unfed aquaculture becomes vastly more efficient than traditional fish farms and all other forms of meat farms. In fact, according to a study conducted by Sustainable Fisheries Group of UC Santa Barbara, this source of food produced fewer CO2 emissions than all other sources of production including rice and only being beaten out by wheat, brown kelp, and soybeans, and used virtually no freshwater, took up less land area than all other crops and livestock in a simulated environment to sustain the entire world using each specific food source. Currently, however, mussel and other shellfish farming are relatively uncommon throughout the world and persuading the society to adopt these more efficient food sources as a future of consumption is a rather daunting task indeed.
Although fish farming and unfed aquaculture are far from mass scale public adoption, the prospect for a future of more sustainable food sources imposes greater potential for these sources of nutrients as demands for more and more food are pushed forth by a growing world population. In an effort to combat climate change, a key shift that must occur is the decrease in reliance of Americans on inefficient farming sources such as pork and cattle in exchange for more sustainable aquaculture alternatives. Overall, the emerging field of aquaculture as a means of mass-scale food production proposes a promising alternative to the conventional agricultural norms of the past.